Recent hydrodynamic simulations of galaxy formation reveal streams of cold (T ∼ 10 K) gas flowing into the centers of dark matter halos as massive as 10M⊙ at redshifts z ∼ 1–3. In this paper we show that if > ∼ 10% of the gravitational binding energy of the gas is radiated away, then the simulated cold flows are spatially extended Lyα sources with luminosities, Lyα line widths, and number densi...

virial theorem is important for understanding stellar structures. it produces an interesting connection between magnetic and gravitational energies. using the general form of the virial theorem including the magnetic field (toroidal magnetic field), we may explain the solar dynamo model in relation to variations of the magnetic and gravitational energies. we emphasize the role of the gravitatio...

We present a physical analogy which can be used to understand the issues involved in the Principle of Equivalence in so-called spatial flow theories of gravity, and we discuss the essential kinematic properties of the flow which distinguish its gravitational, non-inertial, and inertial modes. We also point out that the acceleration experienced by a body moving in the flow does not always coinci...

In order to present a quantitative indicator for the onset of instability, in this paper, the critical points of a stratified gravitational flow on a slope are found and analyzed. These points are obtained by means of the solution of the two-dimensional Navier-Stokes equations via the standard Arakawa-C finite-difference method. Results show that in the marginal Richardson numbers, the critical...

Virial theorem is important for understanding stellar structures. It produces an interesting connection between magnetic and gravitational energies. Using the general form of the virial theorem including the magnetic field (toroidal magnetic field), we may explain the solar dynamo model in relation to variations of the magnetic and gravitational energies. We emphasize the role of the gravitatio...

The lightest supersymmetric particle, most likely the lightest neutralino, is one of the most prominent particle candidates for cold dark matter (CDM). We show that the primordial spectrum of density fluctuations in neutralino CDM has a sharp cut-off, induced by two different damping mechanisms. During the kinetic decoupling of neutralinos, non-equilibrium processes constitute viscosity effects...